lib/zold/amount.rb in zold-0.8 vs lib/zold/amount.rb in zold-0.9

@@ -25,30 +25,38 @@
 # Copyright:: Copyright (c) 2018 Yegor Bugayenko
 # License:: MIT
 module Zold
   # Amount
   class Amount
+    # How many zents are in one ZLD: 2^FRACTION
+    FRACTION = 32
+
+    # Maximum amount of zents
+    MAX = 2**63
+
     def initialize(coins: nil, zld: nil)
       if !coins.nil?
         raise "Integer is required, while #{coins.class} provided: #{coins}" unless coins.is_a?(Integer)
         @coins = coins
       elsif !zld.nil?
         raise "Float is required, while #{zld.class} provided: #{zld}" unless zld.is_a?(Float)
-        @coins = (zld * 2**24).to_i
+        @coins = (zld * 2**Amount::FRACTION).to_i
       else
         raise 'You can\'t specify both coints and zld'
       end
+      raise "The amount is too big: #{@coins}" if @coins > Amount::MAX
+      raise "The amount is too small: #{@coins}" if @coins < -Amount::MAX
     end
 
     ZERO = Amount.new(coins: 0)
 
     def to_i
       @coins
     end
 
     def to_zld
-      format('%0.2f', @coins.to_f / 2**24)
+      format('%0.2f', @coins.to_f / 2**Amount::FRACTION)
     end
 
     def to_s
       text = "#{to_zld}ZLD"
       if negative?
@@ -96,10 +104,10 @@
       @coins < 0
     end
 
     def *(other)
       c = (@coins * other).to_i
-      raise "Overflow, can't multiply #{@coins} by #{m}" if c > 2**63
+      raise "Overflow, can't multiply #{@coins} by #{m}" if c > Amount::MAX
       Amount.new(coins: c)
     end
   end
 end